[tip:x86/asm] oprofile/x86: Add regs->ip to oprofile trace

[tip-bot for Josh Poimboeuf]

Commit-ID:  3e344a0db900757caaf0beeb749de4c7b59bfd60
Gitweb:     http://git.kernel.org/tip/3e344a0db900757caaf0beeb749de4c7b59bfd60
Author:     Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Wed, 24 Aug 2016 11:50:15 -0500
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 8 Sep 2016 08:58:40 +0200

oprofile/x86: Add regs->ip to oprofile trace

dump_trace() doesn't add the interrupted instruction's address to the
trace, so add it manually.  This makes the profile more useful, and also
makes it more consistent with what perf profiling does.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Acked-by: Robert Richter <rric@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Byungchul Park <byungchul.park@xxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Nilay Vaish <nilayvaish@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/6c745a83dbd69fc6857ef9b2f8be0f011d775936.1472057064.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/oprofile/backtrace.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
index cb31a44..2ef6c8b 100644
--- a/arch/x86/oprofile/backtrace.c
+++ b/arch/x86/oprofile/backtrace.c
@@ -114,9 +114,16 @@ x86_backtrace(struct pt_regs * const regs, unsigned int depth)
 
 	if (!user_mode(regs)) {
 		unsigned long stack = kernel_stack_pointer(regs);
-		if (depth)
-			dump_trace(NULL, regs, (unsigned long *)stack, 0,
-				   &backtrace_ops, &depth);
+
+		if (!depth)
+			return;
+
+		oprofile_add_trace(regs->ip);
+		if (!--depth)
+			return;
+
+		dump_trace(NULL, regs, (unsigned long *)stack, 0,
+			   &backtrace_ops, &depth);
 		return;
 	}